There has been too much death of innocents, and too little of the guilty. The problem with death penalty is that people think of death as always "bad". If someone is guilty of murder, getting the death penalty helps to expiate some of their sin (use the word "karma" if you like). Wipes some of the slate clean. Some. So wherever Peterson (or any murderer) goes after death (we're talking the soul, obviously, not the dead body), the suffering he had to experience because of the execution will halp pay for the suffering he caused. With the added benefits of he will never kill anyone again, and the fear and pain may help him take what he's done more seriously, and give him a chance to pray to God for forgiveness.
I used to be a bleeding heart liberal. Many years ago I read an article by another former bleeding heart liberal, who used to teach creative writing in CA state prisons. He wanted to help the prisoners express themselves, and get rehabilitated, and he figured a lot of them came from poor backgrounds, had hard lives, and so on.
After 15 years of this, he made a complete turnaround in his attitude. He used to be against the death penalty, and realized after talking and getting to know literally thousands of prisoners, he became a death penalty advocate. He experienced that none of them (except ONE) actually took any responsibility for their actions - it was all "her" fault, society's fault, their parents' fault, the dog's fault, the cops' fault, the judge's fault. To a man, they considered themselves innocents who just didn't get an even break, while maintaining an exploitative and user mentality to the end.
And, pray tell, who wants to pay for incarcerating all these murderers? I don't.
Send them on their reward or destination; it's actually merciful to everyone concerned.
Can't remember the guy's name of course, but the British doctor who writes for National Review under a pseudonym (Dr. Dalrymple, maybe?) had an article on this very phenomenon a couple of years back.
He also volunteers time as a physician at a prison, and gets to talk to the inmates - and to a man/woman/whatever they all claim that somehow whatever vileness they had committed, just wasn't their fault.
I'm not against the death penalty completely. But I just think there needs to be a little more hard evidence linking him with the murder that's all.